Shoe heel with elastic chambers



June 10, 1952 v. LAMPA ET AL SHOE HEEL WITH ELASTIC CHAMBER Filed June 22. 1949 IN V EN TORS I vAvnm SLAnPA, KAREL Civil-AK, S FRANTISEK VRAGA Patented June 10, 1952 UNITED srArE-is orsi-ce SHOE AHEEL WITH ELASTICI" Vav'nfslampa, :Karel epelk; `amW'rntiiek Vrga, Brunn, Czechoslovakia Application H'June'122, '11949,"fSerialfNo: 1004695 (Cl. 13G-35 ffor'the purposev of increasing the'resiliencyf ofi-.the

tread.

The known rubberiheels ofthe type indicated above, in=which the cavities are enclosedby 1va frameset-vingfortheffastening of the heel to the shoe, :are :wornontin` a comparatively shortrtime. Due `,to `:the felastic deformation of Vthe cavities caused i;by.1compr.ession .and transmittedxto the iframe, the` latterhas va tendency to ,becomeflargen anda1 sliding :onuthessupport is eifected thereby.

-As =a consequence of the lateral sliding, the heel will, zattera-.short time of wear, no longer lie tightly against its support and, upon-walking, iain-willtbe sucked through the gap formedv between-heel'fand :shoeainto the cavities, carrying 'also ,dust.and moisture, This is a serious disadvantage.

zFurthemnore. the friction of the .heel Vonfthe .groundftends to f loosen the fastening means and to shortenthe useful. life'of the heel.

'It isaniobjectzof: the? present invention to provide-.a heelfwhichzallows'to avoid the: above mentioned disadvantages and is not only durablein vuse'but reasytoimanufacture.

`Itisafanotlrier -dbjectzof the invention to provide aheel which'will Akeep .the neat appearance of a new heel 'during'prolonged'wear by'a change'of transmission-of iforces which prevents the fra-me ,from becoming worn down.

Itis2yetzanotheriobject ,of the present inven- ,tiorrto provideia moldzforr simplifying the rmann- :facture otthe improved .eel.

With the aboveobjects. innview, a Ipreferred heel according to ourl invention comprises in combination :a centrally disposed portion, an outer portion circumferentially enclosing the centralportionand means. for attaching the same to a shoe, a plurality of inner cavities arranged in the above mentioned central portion, a plurality of outward bulges 4arranged inthe central portion,- one oppositeeeach of theinner cavities, these outward bulges being of greaterheight than the outer portion circumferentially enclosing the central portion and projectingI beyond thev outer portion, whereby only the bulges are adaptedto form 'thetreading surface of the heel.

,As mentioned above, thezbulges are of'greater Iheightfthanthe frame; they project considerably vbeyond the: frame and, as a' consequence thereof, :therframeis not worn down at all. Thisprovides :aA neat appearance for the heel: .during its-whole life. When a largernumberofbulges is arranged, for example in lthe formof' va circle, the stress is distributed on ample.. treadrsurface. :Wear `is ialso dminishedby. theresiliency of thefbul'ges.

:According to'lthe -inventi`on,rwe further provide "elements lofre'duced cross section, by making channels and thusfforming ribbons or straps, for

conne'ctingthe bulges' with the outerv frame. In

lthiswvafy it isbr'ought :about that the inner portion-ofthe heel formed by the bulges will pivot around .the ribbons 'or straps, while the frame remainsimmovablyifastened to the heel part of the rshoe, without zany :transmission of lateral 'for-ces occurringf-as afconsequence of the resilient `deformationzof the cavities. The drawbacks of th'ecustomary rubber heels are thereby eliminated. Y

The invention "furthermore comprises a form for making'rubber heels as above described in a singIe-step'operaton. AThe. form is made of two separable '1`sections,'-the section for forming the 4rtreadsurface ofthe' heel comprising a depression near the circumference substantially inthe shape fv-afhorse-shoe and adapted to shapea frame on theheeL iat-'plurality of depressions arranged withinthe-horseshoe depression and of greater depth than the fsarne, adapted to form bulges on the heel `of greaterheight .than the frame, and laf pluralityof f elevated f cutting members between the outer depression andthe enclosed depressions adapted for' shaping channels .between the bulges `and timeframe.

The novel features whichwe consider as charfafcteristicforourf invention are set forthl in particular'm the Aappended claims. The invention itselfyrhowe'very. both :as to its construction and its method'cf. operation, together 4with additional AobU'ects-anizl advantages thereof, willbe best ununderstood from the following description of speciic :embodiments Vwhen read. in `connection with :the vaccompanying drawings, in which:

Fig. ilishows the :tread surface of the heel in .pl-an i view.; and

Fig. 2*-.isra'fsectionfalong'line A-B of Fig. l, iliustrating.at'lthesame vtime the form or'mold `for'rnakingflthe heel'accoitding'to the invention.

"Therubber:heelltisflsurrounded by fa frame I fastened? inca :customary "manner by 'pins or screws'i.to.the:heelfoftheshoe at 2. If desired, :the v. rubber heel-.inlay be fastened centrally fas wellsasfcircumferentially, vas shown in Figure l'.

":Theiinnerzportion ofthe heel'is 4formed by a 'number:oflbulgesvyeach underlying and sur- 'roundingaazchamber f4. fIn orderto save'fmaterial, the central 'port-ion 5 of the -heel, which is :not sprovided-'ivith 1a bulge, `may vcontain a "cavitystoa '.Theebulges l. 3; protrude over. the vframe I I and :theVv central Xportionwliw` so thatv y.theyl will extend beyond the frame, and the tread surface -will be; formed entirely vby i-t-he?y bulges. ABetween 'fthe D and C will be slightly increased.- At the same time, ribbons or straps 'I pivot outwardly at their bottom points VE whereby channels 6 are narrowed. The forces are, however, not transmitted to frame I so that this will not be displaced on its supporting face. The pins or screws used for fastening the frame to the heel of the shoe are therefore not stressed or loosened, nor do any frictions occur between the frameand the faces it contacts. No dust or moisture has access to the interior of the cavities L. when by lifting the shoe from its support, that is when the foot is removed rfrom the ground, the bulges resiliently return to their former shape causing at the same time an intake of air by suction into the cavities and a simultaneous widening of the channels.

It is possible to make the channels, which areiso important for the action of ribbons or straps 1, by making cuts into the heels after they have been shaped in the molds. This way of production, however, is cumbersome and expensive, and it was not possible to give the channels the desirable direction at a slant with respect to the tread surface of the heel, which proved to be of advantage in making the ribbons or straps merge into the bulges. f

According to the invention, molds'have now been made which allow the forming of the heel to be combined with the formation of channels 6 in a single operation. The mold according to the invention, which may for instance be made of iron, comprises two portions 8a and 8b; the latter portion, in which the tread surface of the heel is made, contains cutting members II which form the channels 6 at the border between the frame I and the bulges 3.

The cutting members are of such shape and direction that they will form the ribbons or straps with the cross section necessary to allow the above mentioned pivoting of these elements and the free play of Ythe inner portion of the heel formed by bulges 3.

vention as embodied in rubber heels comprising a plurality of cavities arranged in the inner portion and surrounded by a frame, We do not intend to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of our invention.

Without further analysis, the foregoing will so fully reveal the gist of our invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, Vfrom the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention, and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What we claim as new and desire to secure by Letters Patent is: Y

1. A shoe heel having in its bottom face at least one groove extending substantially parallel to the perimeter of the heel spaced therefrom so as to form a narrow rim portion and a central portion, said central portion having a plurality of projecting bulges arranged in a' continuous closed row so as to form a projecting ring adjacent to said rim portion, each of said bulges being formed with an inner cavity and protruding substantially beyond the remainder of said central portion and beyond said rim portion so as to protect the same'from being worn; and means in said rim portion for securing the heel to a shoe.

2. A shoe heel having in its bottomY face'a plurality of grooves arranged in a line extending substantially parallel to the perimeter of the heel spaced therefrom so as to form a narrow rim portion and a central portion, said'central portion having a plurality of projecting bulges arranged in a continuous closed row so as to form a projecting ring adjacent to said rim portion, each of said bulges being formed with an inner cavity and protruding substantially beyond the remainder of said central portion and beyond said rim portion so as to protect the same from being Worn, said bulges Vbeing separated from each other by strip portions of the remainder of the central portionarranged in a star-shaped pattern, each of said grooves extending between one of said bulges and said rim portion between two of said strip portions, and said rim portion After the heels have been formed in a single l l operation, they can easily be removed from the opened mold due to resiliency of the rubber.

It shouldV be noted that the channels 6 do not extend along the entire circumference ofthe inner portion of the heel containing the bulges, but there are interruptions by lands of rubber such as shown at 9; the cutting members of the mold are formed with corresponding interruptions. to the heel. The lands are preferably arranged in line with radially `extending ribs IIJ, each rib I0 being arranged at the level of the central portion 5 between two bulges 3. It is obvious that there may be a greater number of lands 9 than ribs I0, if it is so desired.

It will be readily understood by anybody skilled in theart that instead of using rubber, we may use synthetic rubber or similar materials employed in the art of making heels of the type described.

While we have illustrated and described the in- In'this way, greater strength is imparted l being formed with holes adapted to receive means for securing the heel to a shoe.

'vAvN SLAMPA.' *Y

KAREL EPELK. FRNTISEK VRGA.

REFERENCES CITED The following references are of 'record in the file of this patent:

UNITED STATES PATENTs- Y 'Y 

